Severe weather warnings issued for NSW

Date: January 27 2013

More than 1000 people have been isolated by floodwaters in northern NSW, as people in the state's south are told to prepare for 100km/h winds and flash flooding on Monday.

More than 360 calls for assistance were made to the NSW State Emergency Service (SES) on Sunday, as ex-tropical cyclone Oswald moved across the Queensland border, packing damaging winds and heavy rain.

SES spokesman Phil Campbell told AAP on Sunday evening that there had been no evacuations in NSW's north but around 1300 people had been isolated by floodwaters.

Winds of up to 140km/h hit parts of the northern rivers while flooding on the Bellinger River upstream of Thora had left around 500 people isolated.

"Those people will be isolated for a day or so, they're well prepared and isolation there is quite a regular occurrence," Mr Campbell said.

Another 800 people were isolated by flooding on the upper Clarence River at Ewingar and they were expected to be cut off for two or three days.

Mr Campbell said most calls for assistance to the SES were for leaking roofs and minor property damage from falling trees and branches, mostly in the state's north around Lismore, Grafton and Coffs Harbour.

SES crews on Sunday carried out four flood rescues including that of two people trapped in a car on a causeway near Murwillumbah.

SES spokeswoman Jessica Chan told AAP earlier that emergency crews would focus their efforts south on Monday as Oswald moved south.

"We expect conditions in the north to ease after lunchtime on Monday, with that weather front increases to Sydney.

"We are expecting heavy rainfall and flash flooding."

A severe weather warning was issued for much of the state on Sunday, with the Bureau of Meteorology warning that gusts of 100km/h are forecast for the mid North Coast, the Northern Tablelands, the metropolitan and Hunter during Monday.

"Beach conditions in these areas will be dangerous and people should stay well away from the surf and surf exposed areas," the BoM said.

Heavy rain which may lead to flash flooding is also forecast to extend to the Hunter overnight and to the metropolitan, Central Tablelands and Illawarra districts by Monday afternoon.

But BoM regional director Barry Hanstrum said the low-pressure system will move rapidly and should pass out to sea in the early hours of Tuesday morning.

"The rain and wind will ease from most of NSW on Tuesday as the low moves further offshore and into the Tasman Sea, but dangerous surf will continue into Wednesday," he said in a statement.

The NSW SES urged people returning to NSW's southern cities to be careful.